1. Field of the Invention
This invention relates generally to optical communication networking systems, and more particularly, to a configurable multi-rate network port and associated internal electronic processing modules within a network node.
2. Description of Related Art
The importance of optical networks in today's society is well understood. These optical networks are able to communicate large amounts of data at fast rates. Deployed optical networks may operate at different data rates depending on various factors. For example, certain networks may operate at relatively low optical data rates between 155M to 4.25 GHz. Other networks may operate at relatively high optical data rates above 4.25 GHz.
Optical networks comprise a plurality of optical nodes that communicate information through the network on multiple paths. These nodes include multiple ports on which optical signals are received and transmitted. The nodes also include internal processing modules that analyze received signals and identify a destination for the signal. As a result, an optical signal is received on a port, processed and switched internally within the node, and transmitted on another port corresponding to the destination of the signal.
These networks, and the nodes therein, are often compliant with a particular protocol or standard. This compliance allows the nodes to effectively communicate information between each other and provides the framework in which information may be analyzed internally within the node. Examples of such protocols include Ethernet, SONET, Fibre Channel, and other such protocols known to one of skill in the art.
The components within the nodes may also be defined by standards or recognized requirements. For example, the form factor of port adapters may be defined by one of numerous different standards or requirements, such as SFP, SFP+, XFP, X2, XPAK, and ZenPak. These adapters may also have different signal reaches, bit rates (e.g., 1 G, 2.5 G, or 10 G) and modes (e.g., single or multimode).
As previously discussed, a network node has multiple ports on which information is received and transmitted. These ports are typically defined as either “high speed” or “low speed” ports because of the limitations of its pluggable adapter and associated internal processing modules that analyze data received on the port.
FIG. 1 illustrates an exemplary network node having a plurality of optical ports on which optical signals are received. A low data rate port 130 on which a low frequency optical signal is received and converted to a corresponding electrical signal. The low data rate port 130 is coupled to associated low data rate electronics 145 via low speed SERDES 140 and a low data rate switch. The low data rate switch effectively switches the electrical signal from the low data rate port 130 to one of a plurality of protocol-specific processing modules 125. As a result, the low frequency optical signal is routed from the network node front-end optics to supporting electronic processing modules according to the protocol in which the optical signal was generated.
The low data rate port 130 is typically configured to support optical signals with a low frequency range of about 155M to about 4.25 GHz. The low frequency range may be any other low frequency range as the foregoing range is purely exemplary for the purposes of this disclosure. These supported signals may be either analog or digital, and generated in accordance with various protocols known to one of skill in the art. The low data rate switch 145 effectively switches the electrical signal from the low data rate port 130 to one of a plurality of protocol-specific processing modules 125. In addition, the low data rate port 130 may comprise numerous types of pluggable form factor adapters including, but not limited to, a small form factor pluggable (hereinafter “SFP”).
FIG. 1 further illustrates an exemplary network node wherein a high data rate port 100 on which a high frequency optical signal is received and converted to a corresponding electrical signal. The high data rate port 100 is coupled to associated high data rate electronics 115 via high speed SERDES 110 and a high data rate switch. The high data rate switch 110 effectively switches the electrical signal from the high data rate port 100 to one of a plurality of protocol-specific processing modules 125. As a result, the high frequency optical signal is routed from the network node front-end optics to supporting electronic processing modules according to the protocol in which the optical signal was generated.
The high data rate port 100 is typically configured to support optical signals with a high frequency band of about 8.5 GHz to about 11.1 GHz. The high frequency range may be any other high frequency range as the foregoing range is purely exemplary for the purposes of this disclosure. These supported signals may be either analog or digital, and generated in accordance with various protocols known to one of skill in the art. In addition, the high data rate port 100 may comprise numerous types of pluggable form factor adapters including, but not limited to, SFP+, XFP, X2, XPAK, and ZenPak.
As optical signal rates continually increase, optical components, such as module port adapters, are being generated to support higher rates. For example, an SFP+ adapter has been recently introduced that supports high data rates while having the traditional form factor of an SFP adapter.
One skilled in the art will recognize the limitations of this network node configuration such that optical ports are limited by their associated electronics. In particular, a port is oftentimes exclusively designated as a “high speed” port or a “low speed” port based on the electrical processing modules to which it is coupled. This rigid definition of an optical port limits the adaptability of network nodes and the line cards therein.